1. Field of the Invention
The present invention generally relates to a display device and a light source block used therein. Particularly, the present invention relates to a display device and a light source block used therein for preventing bright bands from occurring at the edge (also called a bright band effect). More particularly, the present invention relates to a liquid crystal display device and a light source block used therein for preventing the bright band effect at the edge.
2. Description of the Prior Art
Because liquid crystal display panels (LCD panels) are characterized by thin, light, convenient, and low radiation compared to CRT display devices, the demand for LCD panels has increased largely. Particularly, a backlight module is one of essential components in the LCD panel. With the advance of the manufacturing technology in LCD panels, the backlight module has become thinner, lighter, brighter, and cost lower. In order to maintain the competitive advantage of LCD panels, developing a high quality backlight module is an important issue.
FIG. 1 is a schematic view of a conventional LCD device. As shown in FIG. 1, a LCD device 10 includes a backlight module 20, a liquid crystal panel 70 disposed on the backlight module 20, and a front frame 90. For the backlight module 20 using lamps as a light source, the backlight module 20 includes a lamp 21, a lamp block 23, and optical films 50. One of the conventional lamp blocks is designed in a form of two pieces including a lamp holder and a frame. Since the two-piece design will increase the cost of molds and productions, the two-piece design is currently replaced with the one-piece design shown in FIG. 1, which integrates the lamp holder and the frame into one piece as an integral lamp block.
With reference to FIG. 1, the lamp block 23 has a reflective surface 25 at the inner lower rim for reflecting the light generated from the lamp 21 so as to increase light usability or brightness. When the lamp block 23 is formed in one piece, the body of the lamp block 23 is conventionally injection-molded by black material, and then, a reflective material is attached to the body as the reflective surface 25. Alternatively, a dual color injection molding process can be adapted to form the reflective surface 25 with white material and the body of the lamp block 23 with black material. However, the above-mentioned technique is higher cost and time consuming. Accordingly, improvements are still required. In the case of directly using white material for injection-molding the lamp block 23, any further process for the reflective surface 25 is not required. However, when the lamp block 23 of white material supports the optical film 50, excessive reflections will occur at the edge of the optical film 50, resulting in bright bands at the edge of the liquid crystal panel 70.